The publication undertook the evaluation in response to the Parity at 10 Campaign, which seeks greater compliance by insurers and state Medicaid programs with the federal Mental Health Parity and Addiction Treatment Act of 2008. The Ohio Council of Behavioral Health and Family Service Providers, representing 150 organizations throughout the state, is the lead Ohio organizer for the national campaign.

Health Affairs notes that while parity is a federal statute, enforcement falls to state authorities for most insurance sources. The journal looked at Ohio's enforcement efforts alongside those of Illinois, Maryland, New Jersey and New York.

Approaches across the states varied, but they often shared challenges, the evaluation found.

For example, Health Affairs wrote that state regulators generally take a "reactive" approach of reviewing forms and responding to complaints, efforts that are "insufficient" to the task. On the topic of complaints, the journal notes many consumers aren't aware of their parity rights and don't know which regulator to contact, leading to a paucity of complaints that reinforces the view there are no parity problems.

Health Affairs also looked at awareness of the law, treatment access problems and the question of political will. "Stakeholders in each of the five states reported a lack of political will to improve parity enforcement in at least one level of state government. Elected officials are concerned about imposing additional regulatory requirements that could lead to increased premiums or a reduced number of carriers participating in state marketplaces," the journal writes.